From 91ec87d57fc38c529034e853687dfb7756de5406 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Thu, 22 Mar 2012 21:15:51 -0700 Subject: x86-64: Simplify and optimize vdso clock_gettime monotonic variants We used to store the wall-to-monotonic offset and the realtime base. It's faster to precompute the monotonic base. This is about a 3% speedup on Sandy Bridge for CLOCK_MONOTONIC. It's much more impressive for CLOCK_MONOTONIC_COARSE. Signed-off-by: Andy Lutomirski Signed-off-by: John Stultz --- arch/x86/include/asm/vgtod.h | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/vgtod.h b/arch/x86/include/asm/vgtod.h index 1f007178c813..8b38be2de9e1 100644 --- a/arch/x86/include/asm/vgtod.h +++ b/arch/x86/include/asm/vgtod.h @@ -7,11 +7,6 @@ struct vsyscall_gtod_data { seqcount_t seq; - /* open coded 'struct timespec' */ - time_t wall_time_sec; - u32 wall_time_nsec; - - struct timezone sys_tz; struct { /* extract of a clocksource struct */ int vclock_mode; cycle_t cycle_last; @@ -19,8 +14,16 @@ struct vsyscall_gtod_data { u32 mult; u32 shift; } clock; - struct timespec wall_to_monotonic; + + /* open coded 'struct timespec' */ + time_t wall_time_sec; + u32 wall_time_nsec; + u32 monotonic_time_nsec; + time_t monotonic_time_sec; + + struct timezone sys_tz; struct timespec wall_time_coarse; + struct timespec monotonic_time_coarse; }; extern struct vsyscall_gtod_data vsyscall_gtod_data; -- cgit v1.2.3